[gnome-control-center/wip/feborges/round-and-generate-user-images: 3/3] user-accounts: Generate a default avatar for new users

[Felipe Borges <felipeborges src gnome org>]

commit ba29519819bd997678e05b973fef501c5ac2373f
Author: Felipe Borges <felipeborges gnome org>
Date:   Mon Feb 4 15:46:16 2019 +0000

    user-accounts: Generate a default avatar for new users
    
    When a user is created, we generate an avatar with their initials.
    
    See https://gitlab.gnome.org/GNOME/Initiatives/issues/6

 panels/user-accounts/cc-user-panel.c |   1 +
 panels/user-accounts/user-utils.c    | 141 +++++++++++++++++++++++++++++++++++
 panels/user-accounts/user-utils.h    |   2 +
 3 files changed, 144 insertions(+)
---
diff --git a/panels/user-accounts/cc-user-panel.c b/panels/user-accounts/cc-user-panel.c
index ab933e47f..e79c39fab 100644
--- a/panels/user-accounts/cc-user-panel.c
+++ b/panels/user-accounts/cc-user-panel.c
@@ -364,6 +364,7 @@ add_user (CcUserPanel *self)
         gtk_dialog_run (GTK_DIALOG (dialog));
 
         user = cc_add_user_dialog_get_user (dialog);
+        generate_user_avatar (user);
         if (user != NULL)
                 reload_users (self, user);
 
diff --git a/panels/user-accounts/user-utils.c b/panels/user-accounts/user-utils.c
index 177a88a11..1a6ff6af8 100644
--- a/panels/user-accounts/user-utils.c
+++ b/panels/user-accounts/user-utils.c
@@ -475,3 +475,144 @@ round_image (const gchar *icon_file,
 
         return dest;
 }
+
+#define IMAGE_SIZE 512
+
+static gchar *
+extract_initials_from_name (const gchar *name)
+{
+        GString *initials = g_string_new ("");
+        gchar *p;
+        gchar *normalized;
+        gunichar unichar;
+
+        p = g_utf8_strup (name, -1);
+        normalized = g_utf8_normalize (g_strstrip (p), -1, G_NORMALIZE_DEFAULT_COMPOSE);
+        g_clear_pointer (&p, g_free);
+        if (normalized == NULL) {
+                g_free (normalized);
+
+                return NULL;
+        }
+
+        unichar = g_utf8_get_char (normalized);
+        g_string_append_unichar (initials, unichar);
+
+        p = g_utf8_strrchr (normalized, -1, ' ');
+        if (p != NULL && g_utf8_next_char (p) != NULL) {
+                p = g_utf8_next_char (p);
+
+                unichar = g_utf8_get_char (p);
+                g_string_append_unichar (initials, unichar);
+        }
+
+        g_free (normalized);
+
+        return g_string_free (initials, FALSE);
+}
+
+static GdkRGBA
+get_color_for_name (const gchar *name)
+{
+        // https://gitlab.gnome.org/Community/Design/HIG-app-icons/blob/master/GNOME%20HIG.gpl
+        static gdouble gnome_color_palette[][3] = {
+                {  98, 160, 234 },
+                {  53, 132, 228 },
+                {  28, 113, 216 },
+                {  26,  95, 180 },
+                {  87, 227, 137 },
+                {  51, 209, 122 },
+                {  46, 194, 126 },
+                {  38, 162, 105 },
+                { 248, 228,  92 },
+                { 246, 211,  45 },
+                { 245, 194,  17 },
+                { 229, 165,  10 },
+                { 255, 163,  72 },
+                { 255, 120,   0 },
+                { 230,  97,   0 },
+                { 198,  70,   0 },
+                { 237,  51,  59 },
+                { 224,  27,  36 },
+                { 192,  28,  40 },
+                { 165,  29,  45 },
+                { 192,  97, 203 },
+                { 163,  71, 186 },
+                { 129,  61, 156 },
+                {  97,  53, 131 },
+                { 181, 131,  90 },
+                { 152, 106,  68 },
+                { 134,  94,  60 },
+                {  99,  69,  44 }
+        };
+
+        GdkRGBA color = { 255, 255, 255, 1.0 };
+        guint hash;
+        gint number_of_colors;
+        gint idx;
+
+        if (name == NULL || strlen (name) == 0)
+                return color;
+
+        hash = g_str_hash (name);
+        number_of_colors = G_N_ELEMENTS (gnome_color_palette);
+        idx = hash % number_of_colors;
+
+        color.red   = gnome_color_palette[idx][0];
+        color.green = gnome_color_palette[idx][1];
+        color.blue  = gnome_color_palette[idx][2];
+
+        return color;
+}
+
+static cairo_surface_t *
+generate_user_picture (const gchar *name) {
+        PangoFontDescription *font_desc;
+        g_autofree gchar *initials = extract_initials_from_name (name);
+        g_autofree gchar *font = g_strdup_printf ("Sans %d", (int)ceil (IMAGE_SIZE / 2.5));
+        PangoLayout *layout;
+        GdkRGBA color = get_color_for_name (name);
+        cairo_surface_t *surface;
+        gint width, height;
+        cairo_t *cr;
+
+        surface = cairo_image_surface_create (CAIRO_FORMAT_ARGB32,
+                                              IMAGE_SIZE,
+                                              IMAGE_SIZE);
+        cr = cairo_create (surface);
+
+        cairo_arc (cr, IMAGE_SIZE/2, IMAGE_SIZE/2, IMAGE_SIZE/2, 0, 2 * G_PI);
+        cairo_set_source_rgb (cr, color.red/255.0, color.green/255.0, color.blue/255.0);
+        cairo_fill (cr);
+
+        /* Draw the initials on top */
+        cairo_set_source_rgb (cr, 1.0, 1.0, 1.0);
+        layout = pango_cairo_create_layout (cr);
+        pango_layout_set_text (layout, initials, -1);
+        font_desc = pango_font_description_from_string (font);
+        pango_layout_set_font_description (layout, font_desc);
+        pango_font_description_free (font_desc);
+
+        pango_layout_get_size (layout, &width, &height);
+        cairo_translate (cr, IMAGE_SIZE/2, IMAGE_SIZE/2);
+        cairo_move_to (cr, - ((double)width / PANGO_SCALE)/2, - ((double)height/PANGO_SCALE)/2);
+        pango_cairo_show_layout (cr, layout);
+        cairo_destroy (cr);
+
+        return surface;
+}
+
+void
+generate_user_avatar (ActUser *user)
+{
+        g_autofree gchar *filename = NULL;
+        cairo_surface_t *surface;
+
+        surface = generate_user_picture (act_user_get_real_name (user));
+
+        /* Save into a tmp file that later gets copied by AccountsService */
+        filename = g_build_filename (g_get_user_runtime_dir (), "avatar.png", NULL);
+        cairo_surface_write_to_png (surface, filename);
+
+        act_user_set_icon_file (user, filename);
+}
diff --git a/panels/user-accounts/user-utils.h b/panels/user-accounts/user-utils.h
index 85b100421..fd2424a04 100644
--- a/panels/user-accounts/user-utils.h
+++ b/panels/user-accounts/user-utils.h
@@ -21,6 +21,7 @@
 #pragma once
 
 #include <gtk/gtk.h>
+#include <act/act.h>
 
 G_BEGIN_DECLS
 
@@ -44,4 +45,5 @@ gboolean is_valid_username                (const gchar *name,
                                            gchar      **tip);
 GdkPixbuf *round_image                    (const gchar *icon_file,
                                            gint         icon_size);
+void       generate_user_avatar           (ActUser *user);
 G_END_DECLS